title: An unusual fragmentation of oxetane-embedded tetracyclic ketal systems.
abstract: An unusual route for the synthesis of functionalized cyclobutane derivatives starting from functionalized norbornane derivatives is reported. Base-induced fragmentation of an oxetanol-type moiety embedded in a tetracyclic norbornyl ketal leads to a cyclobutane-fused derivative as the major or exclusive product. The fragmentation reaction for bridgehead-bromine-substituted derivatives was much faster than for the corresponding chlorine-substituted substrates. The functionalized cyclobutane product was formed exclusively in high yield in the former case, while the latter furnished a minor uncyclized side product in varying yields.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Kanpur , Kanpur-208016, India.
authors.forename: G Hari Mangeswara
authors.initials: GH
authors.lastname: Rao
authors.forename: Faiz Ahmed
authors.initials: FA
authors.lastname: Khan